Do you have a colleague at work or school who just drives you batty? Get revenge on them the smart way. This clever little device will haunt their office or dorm room without leaving a trace. It’s a tiny little magnetic thing that will stick to any metal surface and emit unsettling creaking noises, scratching sounds, gasping breaths, and eerie whispering every six minutes. Seriously, this is the best idea since sliced bread. And it’s only 17 bucks.